Strainer



Feb. 15,1927. 7

J. WILKINSON STRAINER Filed April 25, 1925 Inventor.

Jocmes Wilkinson, e His Attorneg.

Patented Feb. 15, 1927.

JAMES WILKINSON,.OF L Y'NN, 1VIASSACHUSETTS, ASSIGNOR TO GENERAL ELECTR IC COMPANY, A CORPORATION OF NEW YORK.

STRAINEB.

Application filed April 2'5, 1925. Serial No. 25,896.

.made of wireof a strength sufficient to afford the required protection,- itpresents openings for flow through it equal to but about g'of its-total area. Inother words, its eifective flow area is equal to about its overallarea. As a result, in placing such astrainer in a pipe line, it is necessary to provide a strainer of a diameter considerably greater than the diameter of the pipe line in order to obtain the required area of opening. For example,in the case of an 18 inch pipe, it is necessary to'provide a wire strainer of the order of inches di- .ameter to providethe necessary flow area.

This means that a large strainer casing must be provided and also one ofconsiderable length so as to properly direct the steam to and from the strainer. Even then there is considerable loss in such a strainer.

The primary object of my invention is to provide an improved strainer which will give the required total effective. flowv area and which will have the required strength while at the same time it need be but little larger in diameter than the pipe line with sectional vieW of a strainer embodying my invention; Fig. 2 is a transverse sectional View thereof; Fig. 8 1s a perspectlve view on a large scale of a part of the strainer,

and Fig. 4 is a detail sectional view on a still larger scale of one of the cross plates.

Referring to the drawing, 5 indicates a strainer casing having flanges 6 enabling it to be bolted into a pipe line. In it is an opening 7 through which the strainer is ins'erted, the opening being closed by a cover plate Sfastened in position by bolts 9.

The strainer comprises a rim 10 within which are two sets of strips 11 and 12 Which extend at a right angle to each other. The strips 12 areprovided with notches or slots 18 in .which strips 11 fit. of a depth such that the strips overlap each other but partway, the strips 11 projecting.

beyond strips 12 on the up stream side of the strainer, and the strips 12 projecting beyond strips 11 on the down stream side of the strainer.v In the present instance, strips .11 are shown as being made of thicker material than'strips 12 and certain of them,

as is indicated at:14;, are made of greater width than the others to give strength to thestructure. The strips may be fastened together and to rim 10 in any suitable manner. Preferably I connect them together by fused metal, for example by brazing or welding, as this gives a strong unitary structure. In casing 5 is a groove 15 in which rim 10 fits, the inner edge of the rim being flushed with the surface of the casing. The up stream edges of strips 11 are rounded so as to direct the flow smoothly, and the down stream edges of strips 12 are sharpened as shown'particularly in Figl.

With the above described arrangement, it will be seen that there are provided a multiplicity of cellular passages and'that these passages are smallest in the region where the strips overlap, i. e., at their central portions, and are-of greater area in advance of and beyond such central portions. This, as will be clear, is due to the These notches are 4 fact that the strips overlap each other but 7 part way; As a result, there is provided through the strainer multiple Venturi shaped passages, and because of their Ven turi shape, they efiect the passage of the steam with but little loss, reconversion of. velocity into pressure taking placebetween the discharge edges of plates 12.

Because of their width, strips 11 and 12 may be made of comparatively thin stock. and still give the required strength. For example in certain cases, I have found it satisfactory to make strips 11 of material 1/32 thickand strips 12 of material 1/64 thick. Preferably the notches 13 are punched in the strips of the thinner material for manufacturing reasons although they may be otherwise arranged.

Cal

lVith the above described arrangement, I have found that I can produce a strainer having an effectiveflow area, that is, a total passage area, equal to about 75% of the area of the strainer. As a result a strainer embodying my invention need be not nearly so large as in the case of an ordinary wire strainer. Taking for example the case of a strainer for an 18 inch pipe as hereinbetore referred to, a strainer for this size pipc embodying my invention need have a diameter of only about 22 inches as opposed to a strainer of the order not 30 inches diameter when made of wire after the ordinary manner. its a result, my improved strainer is much smaller in size. Furthermore, because of its Venturi shaped passage, itintroduces a much smaller loss into the pipe line. Also, since my improved strainer is required to be of a diameter but little greater than the pipe diameter in which it is used, I am enabled to provide a much smaller angle of approach to and recession from the strainer without increasing the length of the strainer casing; For example, in the case of fluid flow through a diverging pipe section, the angle of the diverging section should be ordinarily not greater than 7 degrees to obtain the best results. By my invention, I am enabled to use an angle of this order and still need only a comparatively short strainer casing, and in the drawing, Fig. 1, it will be noted that the angle of approach to and recession from the strainer proper is of such low value. This functions to minimize the losses in the strainer,

In accordance with the provisions of the patent statute-s, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown and described is only illustrative and that the invention may be carried out by other means.

iVhat I claim as new and desire to secure by Letters Patent of the United States, is:

1. A strainer comprising two sets of thin fiat strips, the strips of one set crossing the strips ofthe other set and said sets of strips partially overlapping each other whereby on each side of the strainer the ed es of one set of strips project beyond the adjacent edges of the other set of strips. 7

2. A. strainer comprisin sets of thin flat strips arranged crosswise relatively to each other and partially overlapping each other, whereby on each side of the strainer the edges of one set oi strips project beyond the edges of the other set of strips, the projecting edgesv on the down stream side of the strainer being tapered toward their free ends.

fused metal, said strips having notches whereby the strips of one set partially overlap the strips of the other set. p

In witness whereof, I have hereunto set my hand this 23rd day of April, 1925.

JAMES WILKINSON. 

